The applications of aerobic granular sludge for leachate treatment: A review

Abstract

The vast majority of the world's daily municipal solid waste (MSW) is dumped in landfills without being treated first. Leachate generated from these landfills is defined as dark-coloured, highly contaminated wastewater that has become a problem for the environment, posing a threat to soil, surface water, and groundwater quality and having a detrimental influence on human health. Thus, leachate treatment is strongly recommended prior to final discharge. The application of aerobic granular sludge (AGS) technology for wastewater treatment has increased in recent years, especially for industrial wastewater such as leachate. Due to its significant advantages over conventional activated sludge technology, such as denser structure, improved settleability, faster effluent separation, higher biomass content, and improved shock loading resistance, AGS is a viable option for leachate treatment. This article provides detailed discussions of the leachate characteristics along with the available treatment systems, focusing on the AGS system. The efficacy of AGS technology in the treatment of landfill leachate was elucidated by highlighting its benefits, governing factors affecting its performance, and limitations. Based on the latest literature, this paper attempts to identify the research gaps and obstacles in using AGS technology for landfill leachate treatment.